Impact Absorbing Structure of a Vehicle

Abstract

To provide a shock absorption structure for a vehicle that is increased in energy absorption efficiency during pedestrian protection without spoiling a bending function of a shock absorber in a case of a light collision.SOLUTION: A shock absorption structure comprises a plate-like shock absorber 11 which extends along a vehicle width, and the shock absorber 11 includes a plurality of upper ribs 18 formed on a top surface of a main wall 15 to extend in a front-rear direction and arranged at intervals in the vehicle width direction, and a plurality of lower ribs 19 formed on a reverse surface of the main wall 15 to extend in the front-rear direction and arranged at intervals in the vehicle width direction, wherein the respective upper ribs 18 have front ends connected to a front wall 16, and at least one lower rib 19 has a bending starting-point part 19a brittler than any other part on its rear end side.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a shock absorption structure of a vehicle provided with a shock absorber extending in the vehicle width direction.

Background Art

[0002] As a shock absorption structure of a vehicle, there has been proposed one provided with a resin plate member whose rear end is attached to the front surface portion of a shroud lower and whose front end extends to a position adjacent to the back surface of a bumper face (see, for example, Patent Document 1). In the shock absorption structure described in Patent Document 1, the plate member includes a flat plate portion, a front piece extending downward from the front end of the flat plate portion, a vertical wall portion extending downward from the rear end of the flat plate portion, a plurality of vertical ribs extending in the front-rear direction on the lower surface of the flat plate portion with a space therebetween in the vehicle width direction, and a plurality of transverse ribs for reinforcement extending in the vehicle width direction on the lower surface of the flat plate portion with a space therebetween in the front-rear direction. A plurality of notches are formed in each vertical rib as a vulnerable portion for a load in the front-rear direction corresponding to the intermediate portion in the front-rear direction of the plate member.

[0003] In Patent Document 1, with this shock absorption structure, when a vehicle collides with a pedestrian, it is said that the plate member sweeps the pedestrian's foot and tilts the upper body onto the bonnet, preventing secondary damage to the pedestrian. In this case, it is described that even if there are notches, the plate member does not buckle or bend. Further, in Patent Document 1, at the time of a minor collision of a vehicle in which a load larger than the collision load on a pedestrian acts, due to the presence of the notches as vulnerable portions, the plate member bends to absorb the minor collision energy, so that the load transmission to the shroud lower behind it is significantly reduced, and it is said that breakage of this shroud lower or shroud can be prevented.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the shock absorption structure of the vehicle described in Patent Document 1, since the notch is formed in the middle portion in the front-rear direction of the vertical rib, it is difficult to cause the vertical rib to undergo buckling deformation during a collision with a pedestrian, and the vertical rib cannot be utilized for energy absorption, resulting in poor efficiency.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a shock absorption structure for a vehicle that increases the energy absorption efficiency during pedestrian protection without impairing the bending function of the shock absorber during a minor collision or the like.

Means for Solving the Problems

[0007] According to the present invention, there is provided a shock absorber for a vehicle, which is installed on the front end side of the vehicle and includes a plate-shaped shock absorber extending in the vehicle width direction. The shock absorber has a main wall extending substantially in the front-rear direction and a front wall extending substantially upward from the front end side of the main wall. The shock absorber includes a plurality of upper ribs formed on the upper surface of the main wall and extending in the front-rear direction and spaced apart in the vehicle width direction, and a plurality of lower ribs formed on the lower surface of the main wall and extending in the front-rear direction and spaced apart in the vehicle width direction. Each upper rib has a front end connected to the front wall, and at least one of the lower ribs has a bending starting portion that is more vulnerable than other portions on the rear end side, thereby providing a shock absorption structure for a vehicle.

[0008] According to this shock absorption structure of the vehicle, at the time of a collision with a pedestrian or the like, since the upper ribs and the lower ribs are formed on the main wall, the main wall of the shock absorber, the upper ribs, and the lower ribs can be buckled while maintaining the posture of the main wall by the upper ribs and the lower ribs. Here, since the bending starting portion is formed on the rear end side of the lower rib, it is not the case that it is difficult to cause the lower rib to undergo buckling deformation as if the bending starting portion were formed at the center in the front-rear direction of the lower rib. In this way, by buckling the upper ribs and the lower ribs in addition to the main wall, the amount of energy absorbed during pedestrian protection can be increased. Also, in the case of a minor collision of the vehicle where a load greater than the collision load on a pedestrian or the like acts, energy absorption is achieved by bending the main wall convex upward starting from the bending starting point portion on the rear end side of the lower rib.

[0009] Further, in the shock absorption structure of the vehicle, the main wall may be formed to slope downward, and the front end of each upper rib may be disposed below the bending starting point portion of the lower rib in the vertical direction.

[0010] According to this shock absorption structure of the vehicle, the load from the collision object to the rear is mainly transmitted from the front wall to the main wall and the upper ribs, and a force in the bending direction upward is generated in the main wall formed to slope downward. And since the front end of the upper rib is formed lower than the bending starting point portion of the lower rib, the front end side of the upper rib can be easily moved downward around the vicinity of the bending starting point portion of the lower rib as a central axis, and a deformation mode in which the main wall is surely bent convex upward can be achieved.

[0011] Further, in the shock absorption structure of the vehicle, each of the upper ribs may be formed such that the vertical dimension increases toward the front.

[0012] According to this shock absorption structure of the vehicle, an increase in the energy absorption amount of each upper rib at the initial stage of a collision with a pedestrian or the like can be achieved.

[0013] Further, in the shock absorption structure of the vehicle, the bending starting point portion of the lower rib may include a notch formed at the lower end of the lower rib.

[0014] According to this shock absorption structure of the vehicle, at the time of a minor collision of the vehicle or the like, the main wall is bent starting from the notch of the lower rib.

[0015] Further, in the shock absorption structure of the vehicle, the bending starting point portion of the lower rib may include a thin portion formed thinner than other portions.

[0016] According to the shock absorption structure of this vehicle, during a minor collision of the vehicle or the like, the main wall is bent starting from the thin portion of the lower rib.

Advantages of the Invention

[0017] According to the shock absorption structure of the vehicle of the present invention, it is possible to increase the energy absorption efficiency during pedestrian protection without impairing the bending function of the shock absorber during a minor collision or the like.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0019] Figures 1 to 6 show an embodiment of the present invention. Figure 1 is an external perspective view of a vehicle, Figure 2 is a perspective explanatory view of the front part of the vehicle body, Figure 3 is an exploded perspective explanatory view of the shock absorption structure, Figure 4 is a side sectional view of the lower shock absorption part, Figure 5 is a partial perspective view of the lower shock absorption part seen from below, and Figure 6 is an operation explanatory view of the lower shock absorption part showing a state in which the shock absorber is bent starting from the bending starting part during a vehicle collision.

[0020] As shown in FIG. 1, the shock absorption structure of this vehicle 100 is provided behind the bumper face 101 that forms the design surface at the front end of the vehicle 100. As shown in FIG. 2, a plurality of shock absorption parts 1, 2, and 3 extending in the vehicle width direction are provided behind the bumper face 100. In FIG. 2, for the sake of explanation, a state where the bumper face 100 is removed from the vehicle body 4 side is shown. In the present embodiment, three shock absorption parts, namely, the lower shock absorption part 1, the center shock absorption part 2, and the upper shock absorption part 3, are provided. Each of the shock absorption parts 1, 2, and 3 is fixed to a predetermined position of the vehicle body 4, respectively.

[0021] As shown in FIG. 2, the vehicle body 4 is formed by integrating panel-shaped members obtained by press-forming, for example, steel plates, and joining them by spot welding or the like. The vehicle body 4 includes a pair of left and right side frames (not shown) extending in the front-rear direction, a bumper beam 41 that connects the front ends of the respective side frames via brackets and extends in the vehicle width direction, a pair of left and right radiator panels 42 that are connected to the front end sides of the respective side frames and extend in the vertical direction, a radiator lower support 43 that connects the lower ends of the respective radiator panels 42 and extends in the vehicle width direction, a radiator upper support 44 that connects the upper ends of the respective radiator panels 42 and extends in the vehicle width direction, and a pair of connection members 45 that connect the vehicle width direction ends of the radiator upper support 44 and a pair of left and right upper frames (not shown) extending in the front-rear direction. The bumper beam 41 is formed longer than the radiator upper support 44 in the vehicle width direction, and a pair of left and right headlamps (not shown) are arranged outside the radiator upper support 44 in the vehicle width direction.

[0022] In addition, the vehicle body 4 includes a sub-frame 46. The sub-frame 46 has a pair of left and right front-rear extending parts 46a that extend in the front-rear direction below the respective side frames, and a vehicle width extending part 46b that connects the front ends of the respective front-rear extending parts 46a and extends in the vehicle width direction. The vehicle width extending part 46b is arranged in front of the radiator lower support 43.

[0023] As shown in FIG. 3, the lower shock absorber 1 is provided on the front side of the vehicle-width extending portion 46b of the sub-frame 46. In the present embodiment, the lower shock absorber 1 is divided into a front shock absorber 11 and a rear base portion 12, and the shock absorber 11 and the base portion 12 are integrally provided on the vehicle body 4. The shock absorber 11 and the base portion 12 are fastened by a plurality of fastening portions 13. The material of the lower shock absorber 1 is arbitrary, for example, it can be made of resin. In the present embodiment, the shock absorber 11 and the base portion 12 are made of non-foamed polypropylene.

[0024] The center-side shock absorber 2 is provided on the front side of the bumper beam 41. In the present embodiment, the center-side shock absorber 2 is divided into a front portion 21 and a rear portion 22, and the front portion 21 and the rear portion 22 are integrally provided on the vehicle body 4. The material of the center-side shock absorber 2 is arbitrary, for example, it can be made of metal, resin, etc. In the present embodiment, the front portion 21 is made of non-foamed polypropylene, and the rear portion 22 is made of foamed polypropylene.

[0025] The upper shock absorber 3 is provided on the front side of the radiator upper support 44. As shown in FIG. 3, the upper shock absorber 3 has a front portion 31 whose front end forms a collision portion with the collision body, and a bracket portion 32 interposed between the front portion 31 and the vehicle body 4. The material of the upper shock absorber 3 is arbitrary, for example, it can be made of metal. In the present embodiment, the front portion 31 and the bracket portion 32 are made of steel plates.

[0026] The shock absorber 11 of the lower shock absorption part 1 is installed on the front end side of the vehicle, extends in the vehicle width direction, and is formed in a plate shape. As shown in FIG. 3, the shock absorber 11 is formed such that the central side extends substantially in the vehicle width direction in the vehicle width direction, and the outer end side is inclined rearward toward the outside. As shown in FIG. 4, the shock absorber 11 has a rear wall 14 extending in the vertical direction, a main wall 15 extending substantially forward from a predetermined position in the vertical direction of the rear wall 14, and a front wall 16 extending substantially upward from the front end of the main wall 15. The rear wall 14 is formed along the front wall 12a of the base 12. The rear wall 14 has beads 14a formed at intervals in the vehicle width direction and extending vertically. In the present embodiment, the main wall 15 is curved downwardly concave and extends obliquely downward and forward from the upper side of the rear wall 14. Also, the front wall 16 extends obliquely forward and upward from the front end of the main wall 15. In the present embodiment, a chamfered portion 17 is formed between the main wall 15 and the front wall 16.

[0027] The shock absorber 11 has a plurality of upper ribs 18 formed longitudinally on the upper surface of the main wall 15 and arranged at intervals in the vehicle width direction, and a plurality of lower ribs 19 formed longitudinally on the lower surface of the main wall 15 and arranged at intervals in the vehicle width direction. In the present embodiment, each of the upper ribs 18 and each of the lower ribs 19 have a plate shape perpendicular to the vehicle width direction. Incidentally, in the present embodiment, ribs extending in the vehicle width direction are not formed on the upper surface and the lower surface of the main wall 15. Each upper rib 18 has its front end connected to the front wall 16 and its rear end connected to the rear wall 14. In the present embodiment, each upper rib 18 is formed such that its vertical dimension increases toward the front.

[0028] On the one hand, although the rear end of each lower rib 19 is connected to the rear wall 14, the front end is not connected to the front wall 16. In the present embodiment, each lower rib 19 is formed with a substantially constant dimension in the front-rear direction. As shown in FIG. 5, except for a part of the lower ribs 19 on the outer end side in the vehicle width direction, the lower ribs 19 arranged on the center side in the vehicle width direction have notches 19a formed on the rear end side. The front end of each upper rib 18 is arranged below the notch 19a in the vertical direction. In the present embodiment, the notch 19a is formed at the lower end side of the rear end of the lower rib 19 so as not to reach the lower surface of the main wall 15. The formation part of the notch 19a in each lower rib 19 forms a bending starting part that is more fragile than other parts. As shown in FIG. 4, in the present embodiment, the front end of the lower rib 19 is formed to be substantially flush with the chamfered part 17.

[0029] According to the shock absorption structure configured as described above, at the time of a collision with a pedestrian or the like, since the upper ribs 18 and the lower ribs 19 are formed on the main wall 15, the main wall 15, the upper ribs 18, and the lower ribs 19 of the shock absorber 11 can be buckled while maintaining the posture of the main wall 15 by the upper ribs 18 and the lower ribs 19. Here, since the notch 19a is formed on the rear end side of the lower rib 19, it is not the case that it is difficult to buckle the lower rib 19 as if the notch 19a is formed at the center in the front-rear direction of the lower rib 19. Thus, in addition to the main wall 15, by buckling the upper ribs 18 and the lower ribs 19, the energy absorption amount at the time of pedestrian protection can be increased.

[0030] Also, as shown in FIG. 6, during a minor collision of a vehicle in which a load greater than the collision load on a pedestrian or the like acts, energy absorption is achieved by bending the main wall 15 convex upward starting from the notch 19a on the rear end side of the lower rib 19. At this time, since the shock absorber 11 is fastened and fixed to the base portion 12, it does not shift in the vertical direction with respect to the base portion 12, and the bending mode is less likely to become unstable. In the present embodiment, since the lower rib 19 is formed on the main wall 15 over the front and rear, and the notch 19a is formed at the rear end of the lower rib 19, the main wall 15 is bent upward at the rear end. As a result, during a minor collision or the like, it is difficult for damage to reach the vehicle body 4 side beyond the lower shock absorber portion 1. In this way, the energy absorption efficiency during pedestrian protection can be increased without impairing the bending function of the shock absorber 11 during a minor collision or the like.

[0031] In the present embodiment, since the main wall 15 is formed to slope downward toward the front, the load from the collision object toward the rear is mainly transmitted from the front wall 16 to the main wall 15 and the upper rib 18, and a force in the upward bending direction is generated on the main wall 15 formed to slope downward toward the front. And since the front end of the upper rib 18 is formed lower than the notch 19a of the lower rib 19, the front end side of the upper rib 18 can be easily moved downward around the vicinity of the notch 19a of the lower rib 19, and a deformation mode in which the main wall 15 is surely bent convex upward can be achieved.

[0032] Also, in the present embodiment, since the notch 19a is formed in the lower rib 19 on the center side in the vehicle width direction, the shock absorber 11 is more likely to bend upward as a whole along the virtual line connecting the respective notches 19a on the center side in the vehicle width direction. As a result, even when the collision object contacts the shock absorber 11 as a whole in the vehicle width direction, such as in a full lap collision, or when the collision object contacts the shock absorber 11 locally in the vehicle width direction, such as in an offset collision, a deformation mode in which the shock absorber 11 is bent along the above virtual line is more likely to be realized.

[0033] In the above-described embodiment, although the shock absorption structure is shown to include three shock absorption portions, the number of shock absorption portions can be arbitrarily changed. Also, although the lower shock absorption portion to which the present invention is applied is shown to be installed on the subframe, the lower shock absorption portion may be installed on the radiator lower support. Furthermore, the present invention can also be applied to the central shock absorption portion installed on the bumper beam and the upper shock absorption portion installed on the radiator upper support.

[0034] Also, in the above-described embodiment, although the notch 19a is provided as the bending starting point portion of the lower rib, it can also be a thin-walled portion formed thinner than other portions instead of the notch 19a. Furthermore, the bending starting point portion of the lower rib may be made thin and then notches may be provided.

[0035] Also, in the above-described embodiment, although each upper rib 18 is formed such that its vertical dimension increases toward the front, each upper rib 18 may be formed with a substantially constant dimension over the front and rear. Also, in the above-described embodiment, although the main wall 15 is formed to slope downward, for example, even if the main wall 15 is formed substantially horizontally, if a bending starting point portion is formed on the rear end side of the lower rib 19, the main wall 15 can be bent convex upward. Furthermore, in the above-described embodiment, although each upper rib 18 and each lower rib 19 are shown to be formed in the front-rear direction on the main wall 15, they may be formed only in a predetermined section in the front-rear direction. Furthermore, in the above-described embodiment, although the notch 19a is formed in the lower rib 19 on the inner side in the vehicle width direction, it is sufficient that at least one lower rib has a bending starting point portion, and the arrangement state and number of the lower ribs having the bending starting point portion can be appropriately changed.

[0036] The embodiments of the present invention have been described above, but the above-described embodiments do not limit the invention according to the claims. Also, it should be noted that not all combinations of the features described in the embodiments are essential means for solving the problems of the invention.

Explanation of Reference Numerals

[0037] 1 Lower shock absorber 11 Shock absorber 15 Main wall 16 Front wall 18 Upper rib 19 Lower rib 19a Notch 100 Vehicle

Claims

1. It is installed on the front end side of the vehicle and includes a plate-shaped shock absorber extending in the vehicle width direction. The shock absorber has a rear wall extending in the vertical direction, a main wall extending substantially forward from a predetermined position in the vertical direction of the rear wall, and a front wall extending substantially upward from the front end side of the main wall. The rear wall of the shock absorber is fastened and fixed to a base portion located behind the rear wall. The shock absorber includes a plurality of upper ribs formed to extend in the front-rear direction on the upper surface of the main wall and arranged at intervals in the vehicle width direction, and a plurality of lower ribs formed to extend in the front-rear direction on the lower surface of the main wall and arranged at intervals in the vehicle width direction. The front end of each upper rib is connected to the front wall. At least one of the lower ribs has a bending starting portion that is weaker than other portions only at the rear end, and the rear end is connected to the rear wall. A chamfered portion is formed between the main wall and the front wall. A shock absorption structure for a vehicle, wherein the front end of the lower rib is formed to be substantially flush with the chamfered portion.

2. The main wall is formed to slope downward toward the front. The shock absorption structure for a vehicle according to claim 1, wherein the front end of each upper rib is arranged below the bending starting portion of the lower rib in the vertical direction.

3. The shock absorption structure for a vehicle according to claim 1 or 2, wherein each upper rib is formed such that the vertical dimension increases toward the front.

4. The shock absorption structure for a vehicle according to any one of claims 1 to 3, wherein the bending starting portion of the lower rib includes a notch formed at the lower end of the lower rib.

5. The shock absorption structure for a vehicle according to any one of claims 1 to 4, wherein the bending starting portion of the lower rib includes a thin-walled portion formed thinner than other portions.

6. The shock absorption structure for a vehicle according to any one of claims 1 to 5, wherein no ribs extending in the vehicle width direction are formed on the upper and lower surfaces of the main wall.

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